Sex, Symbiosis and Coral Reef Communities

SYNOPSIS. Questions about how today's corals and coral reefs will fare in a future that holds not only increasing direct anthropogenic impacts, but also global change, cannot be satisfactorily answered if we do not understand the relations of corals and reef systems to today's environmental conditions. This paper discusses four aspects of modern reef biology: coral reproduction, coral population biology, the coral-zooxanthella symbiosis, and reef community ecology. Conclusions of this survey of current knowledge are that complexities of cnidarian reproductive biology, and our rudimentary knowledge of reproductive patterns in reef cnidarians, make forecasting based on current knowledge uncertain at best; new discoveries about the coral algal symbiotic system suggest a possible mode of adjustment to environmental change that warrants a strong research effort; coral communities of the future may well be unlike what we are familiar with today; and these new assemblages will be shaped by the interaction of novel environmental conditions and the characteristics of individual reef species.